Air-duct.



C. J. MERRILL.

AIR DUCT.

APPLICATION FILED NOV. 15. 1917.

1 79,739. Patented Sept. 24, 1918.

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UNITED STATES PATENT OFFICE.

CABLE MERRILL, orron'rnnnn, MAINE.

I AIR-DUCT.

i I Specification of Letters Patent! Patentd Sept. 24,

Application filed November 15,1917. Serial 110. 202,175.

tion relates particularly to the problem of forcing a layer of air next to the ceiling of the room for'preventing the moist an of the room from condensing thereon.

The condensation of moist air on. walls and ceilings in rooms where an excessive amount of moisture'is used is a serious evil in many places and this evil is usually met by supplying a large volume of relatively dry air from outside delivered at the upper portion of the room, so as to exclude the moist air from contact with the ceiling.

According to my invention, I provide an air duct close to the ceiling with frequent openings in the sides which discharge parallel streams of air. These parallel streams of air impinging against the ceiling tend to spread out, covering the entire ceiling with a relatively thin layer of air which aifords perfect protection to the ceiling with the least possible quantity of air.

Another feature of my invention is the construction of the air duct itself in which I arrange the air discharge nozzles on the inside of the duct and so located that they will catch the current of air in the duct and divert it in a lateral direction from the duct.

Another feature of my invention covers the manner of forming the nozzle, andthe I manner of fastening it to the duct.

My invention may best be understood by referring to the accompanying drawing in which is illustrated one form of my invention.

In the drawing Figure 1 is a cross section of one of the ducts with the ceiling of the room indicated- Fig. 2 is a longitudinal section of the same.

Fig. 3 is an elevation of the outside of the duct showing one of the nozzles.

Fig. 4 is a perspective of one of the nozzles and,

Fig. 5 is a development of the sheet metal of the nozzle showing it before'it is bent up. In the drawing I have shown but one of the ducts and that ductwith nozzles on only one side, but in practice the ducts are arranged in order covering the ceilingof the room so that the air current will cover substantially the whole area of the ceiling.

The duct 1 is shown as secured close to the ceiling 7 of the room, and is connected with a suitable blower. g

The nozzles for directing the air blast against the ceiling are arranged along the sides of the duct preferably on both sides and are near enough together so that the .1 1

air currents as they issue from the nozzles and aredirected outwardly against the ceiling will spread out into a comparatively thin layer covering the entire ceiling. In practice the nozzles are arranged on an average of about l inches apart, and they are generally inclined upwardly as shown, so that the current will strike the ceiling at an inclination.

The discharge nozzles 2 in the sides of the ducts are arranged on the inside and do not project from the outer surface of the duct. Each nozzle is preferably secured so that the current of air passing through it will have an inclined upward direction. In

some situations as where the duct can come high enough the nozzles and not upward,

Each of the nozzles 2 is made up of a piece of sheet metal, preferably galvanized iron. It is cut in the form shown in Fig. 5 so that it may be bent on the dotted lines and form when bent up, a short nozzle section having a rectangular cross section. The side 5 is the longer side and the opposite side 6 is the shorter side, and the side 6 is point horizontally turned toward the point from which the air blast is coming. In this way the long side 5 intercepts the air current and directs it outwardly and generally in an upward direction from the side of the duct in contact with the ceiling of the room where it spreads out and prevents the moist air from coming in contact with the ceiling and condensing thereon.

After the nozzles have been bent up and formed with flanges 3 at their outer ends to fit against the outside of the duct they are slipped into rectangular openings cut in the side of the duct and fastened securely in It will be seen that a nozzle thus formed" and secured in place as shown, can be made rapidly, requires no soldering to fasten it in place, it presents an unobstructive outer surface for the duct and enables these air ducts to be made cheaply and substantially;

v Such an apparatus as I have described may be erected, with relativelylow cost as far as the construction of the ducts is concerned and it protects the ceiling with the least possible quantity of air since the air spreads out in a thin film and forms the most effective distribution which can be designed. The saving of labor and material in the construction of the nozzles is very considerable and the outside of the duct prevents a smooth and unobstructed surface.

Another reason whythe projected air will form a thin layer is, because the currentis subjected to the slight .upwardpressure of the moist and generally heated air from the body of the room. The dry air is therefore held close to the surface of the ceiling, and

tends thus to spread out thin, rather than to fall and mix with the moist air.

I claim:

1. An outletnozzle for air ducts consisting of a sheet of metal bent to form a short section having a rectangular cross-section fitting in a rectangular opening in the side of the duct, and having flanges turned on the outer end to fit against the outer surface of the duct, the corners of the nozzle being prick-punched inwardly directly inside of the side wall of the duct to expand said corners to hold the section in place.

2. An outlet nozzle for air ducts consisting of a sheet of metal bent to form a short section having a rectangular cross-section fitting in a rectangular opening in the side of the duct, and having flanges turned on its outer ends to fit against the outer surface of the duct, the corners of the nozzle being prick-punched inwardly directly inside of the side wall of the duct to expand the corners for holding the section in place, one side of said section being extended inwardly to intercept the moving current of air in the duct. J v In testimony whereof IatfiX my signature.

CABLE J MERRILL.

copies or this patent may be obtained for five 'cents each by addressing the Commissioner of l'atenti,

Washington, D. U. 

